Cutting out a few aztec calendars with Mach4>ESS. As you'd expect the gcode is huge. the first time I ran it it cut 100% without any issues. the second time, at around 350,000 (60-65% of the way through) it stopped cutting at its set speed of 80ipm and started stuttering and moving the machine extremely jerkily, and mach4 was reading out that it was cutting out at 15-20 ipm, but still jogging at the normal jog speed of 120 when it lifted the spindle.
After pausing and restarting the program it continued on normally, but as the cut got closer to being complete I saw that the XY had been shifted by almost a quarter inch. thats fine, just started a fresh one without letting it finish (4 hour cut time)
Next run it started lagging and jittering again and reading the same low cut speed and normal jog speed at line 115,000 (approximately). I caught it almost right away this time, and when I paused it and resumed it, it ran through the rest of the code without fault. Everything stayed lined up this time as well.
I've been using this machine with Mach3 for over a year now without any issues like this. Just recently got the ESS and Mach4 to switch to a laptop from the old PC it came with.
My question is this:
Where should I start looking to find what is causing this? What information would I need to provide if anyone here has some insight?